Thermal printing element arrays

Abstract

An array of elongated thermal printing elements which may be selectively energized through suitable electrodes connected to the long dimension of the thermal printing elements to thermally print numeric characters or other information.

What is claimed is: 
     
       1. A thermal printing element array for printing selected symbols on a thermographic recording medium comprising: a substrate member;   a plurality of elongated resistive elements supported by said substrate member, said resistive elements being arranged in a pattern so that selective electrical energization of said resistive elements will cause selected symbols to be thermally printed on a thermographic recording medium placed in cooperative relation with said resistive elements; and   a plurality of electrical conductors supported by said substrate member, each of said resistive elements being electrically connected to a pair of said electrical conductors, and each of said electrical conductors being connected along the long dimension of a respective one of said elongated resistive elements so that electrical current path between said conductors is across the short dimensions of said resistive elements.   
     
     
       2. The thermal printing element array of claim 6 further comprising: an isolation layer disposed between said substrate and said resistive elements.   
     
     
       3. The thermal printing element array of claim 1 wherein each said pair of electrical conductors are connected to a respective elongated resistive element along opposite sides thereof. 
     
     
       4. The thermal printing element array of claim 3 wherein a single electrical conductor is connected to one side of each of a plurality of resistive elements, the opposite side of each of said plurality of resistive elements being connected to an individual electrical conductor. 
     
     
       5. The thermal printing element array of claim 3 wherein said electrical conductors comprise a layer of separate areas of electrically conductive material, pairs of areas of electrically conductive material defining the longitudinal edges of elongated spaces therebetween. 
     
     
       6. The thermal printing element array of claim 5 wherein said resistive elements comprise layers of areas of resistive material bridging said elongated spaces between said pairs of areas of electrically conductive material. 
     
     
       7. The thermal printing element array of claim 2 wherein said layer of separate areas of conductive material is superposed over said isolation layer and said layer of areas of resistive material is superposed over said layer of areas of conductive material. 
     
     
       8. The thermal printing element array of claim 2 wherein said electrical conductors are connected to the top and bottom of said elongated resistive elements. 
     
     
       9. The thermal printing element array of claim 8 wherein said plurality of electrical conductors comprises a first layer of electrically conductive material serving as a common electrode for said elongated resistive elements and a second layer of separate elongated areas of electrically conductive material serving as individual electrodes for said resistive elements. 
     
     
       10. The thermal printing element array of claim 9 wherein said resistive elements comprise a layer of resistive material disposed between said first and second layers of electrically conductive material. 
     
     
       11. The thermal printing element array of claim 10 wherein said first layer of electrically conductive material is superposed over said isolation layer, said layer of resistive material is superposed over said first layer of electrically conductive material and said second layer of electrically conductive material is superposed over said layer of resistive material. 
     
     
       12. A thermal printing element array for printing selected symbols on a thermographic recording medium comprising: a substrate member;   a plurality of elongated resistive elements supported by said substrate member, said resistive elements being arranged in a pattern so that selective electrical energization of said resistive elements will cause selected symbols to be thermally printed on a thermographic recording medium placed in cooperative relation with said resistive elements; and   a plurality of electrical conductors supported by said substrate member, each of said resistive elements being electrically connected to a pair of said electrical conductors, and each of said electrical conductors being connected along the long dimension of a respective one of said elongated resistive elements so that electrical current path between said conductors is across the short dimensions of said resistive elements, at least one of said conductors being connected along the long dimensions of at least two resistive elements in common.